Abstract: Support Vector Data Description（SVDD） is a classification algorithm for constructing one-class data description. Penalty parameter[C]and kernel parameter[σ]are two key points to affect the classification performance of SVDD and it has always been a difficulty to select reasonably. Focused on this problem, a parameter optimization algorithm of SVDD based on improved krill algorithm is proposed. Firstly, this paper analyzes the[C]and[σ]parameters’ influence on learning models of SVDD through simulation experiment; Then, this paper introduces the krill herd algorithm and analyzes its merits and demerits, defines the disturbance factor in random diffusion behaviors to enhance the global exploratory; Furthermore, a new elitist election and reserving strategy is introduced into the iterative process to improve the accuracy of convergence; Finally, this paper introduces the improved krill herd algorithm into the parameters optimization process of SVDD and establishes the IKH-SVDD parameters optimization model. Simulation with the UCI benchmark datasets indicates that KH-SVDD has better classification accuracy than the current parameter optimization algorithm.

Key words: support vector data description, improved krill herd algorithm, parameters optimization, elitist election and reserving strategy

摘要： 支持向量数据描述（SVDD）是构造单类数据描述的分类算法，惩罚参数[C]和核参数[σ]作为影响SVDD分类效果的关键，其合理选取一直是个难点。针对这一问题，提出了一种基于改进磷虾群算法的SVDD参数优化算法（IKH-SVDD）。依据仿真实验，分析参数[C]和[σ]对描述边界的影响；引入磷虾群算法并分析其优劣，通过在随机扩散行为中定义扰动因子，增强算法的全局搜索能力；将一种新的精英选择和保留策略引入迭代过程，提高算法的收敛精度；将改进的磷虾群算法引入SVDD参数优化过程，构建了IKH-SVDD参数优化模型。基于UCI标准数据库进行实验并与其他几种参数优化算法进行比较，结果表明了IKH-SVDD算法具有更高的分类准确性。

关键词: 支持向量数据描述, 改进磷虾群算法, 参数优化, 精英选择和保留策略